Respiratory effects from industrial talc exposure among former mining workers

To evaluate late respiratory effects from occupational inhalation of talc contaminated with asbestos.

This was a case series study on 29 former talc mining workers with asbestos contamination, in the municipality of Carandaí, Southeastern Brazil, who were attended at the State Workers' Health Reference Center in 2004 and 2005. Their clinical and occupational histories were obtained and they underwent spirometry and chest radiography. An exposure score was created; multiplying this by duration produced a cumulative talc exposure index. To confirm the association between the cumulative exposure index and the presence of radiological abnormalities suggestive of pneumoconiosis and/or pleural abnormalities, an exact logistic regression model was fitted to this.

All the former workers were males, with an average age of 48.2 years. Chest radiographs showed pleural abnormalities in three of them; parenchymatous opacity compatible with pneumoconiosis in one; and suspected pneumoconiosis in six. Spirometric abnormalities were found in three workers. Logistic regression showed an odds ratio of 1.059 (95% CI: 1.012; 1.125) for the cumulative exposure index, i.e. each unit increase in the index resulted in an increase of 5.9% in the chance of presenting radiological abnormalities compatible with or suspicious of pneumoconiosis. With regard to the median estimated latency period between the start of exposure and the diagnosing of pleural plaque, there was a significant difference (p = 0.013) between the cases (27.0 years) and non-cases (14.3 years).

These findings indicate the need for clinical control among workers who have been exposed to asbestos, particularly because of the late effects from exposure to this mineral.